Method and means of signaling.



PATENTED AUG. 1, 1905.

I. W. PRBNTIGE. METHOD AND MEANS OF SIGNALING.

APPLICATION FILED NOV. 19, 1902.

2 SHEETS-SHEET 1.

No. 795,857. PATENTBD AUG. 1, 1905.

1?. w. P-RENTIOR' METHOD AND MEANS OF SIGNALING.

APPLIOATION FILED NOV. 19, 1902- 2 SHEETS-SHEET 2 Amsrr A Invmmn.

a. WW. BY W 7 M Anr uurrnn STATES PATENT OFFICE.

FRANK \V. PRENTICE, OF BRADDOCK, PENNSYLVANIA, ASSIGNOR, BY

DIRECT AND MESNE ASSIGNMENTS,

OF ONE-HALF TO H. G. REHN,

OF CLEVELAND, OHIO, AND GEORGE D. BRECK, OF PITTSBURG, PENN SYLVANIA.

METHOD AND MEANS OF SIGNALING.

v Specification of Letters iatentf Patented Aug. 1, 19L5.

Application filed, November 19, 1902. Serial No. 131,973-

To all whom, it ntwy concern:

, Be it known that I, FRANK W. PRENTIOE, a citizen of the United States, residing at Braddock, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvementsin the Method and Means for Signaling; and I do declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same. I

My invention relates to a method of conveying the so-called Hertzian wave used in wireless telegraphy and to the means for receiving and utilizing the same for signaling purposes, substantially as shown and described, and more particularly pointed out in the claims.

The established and accepted novelty of the so-called Hertzian wave lies in its adaptation to travel through the ether to any point without other means of conveyance; butin my experiments leading up to this invention, with a view especially to its use on trains to prevent collisions, I discovered that the utilization of the ether was unsatisfactory in many ways, and especially that the transmission of the wave by this means was very unreliable and could not be depended upon. I was thereupon led to make tests of other means of transmission and conveyance and discovered that a metallic conductor would carry the socalled Hertzian wave with far better results and with absolute certainty. I discovered that where a metal conductor was used the said wave could not be grounded and would not be affected by the conditions of the weather or electrical disturbances and that the energy of the wave thus conveyed was far in excess of that same wave when transmitted through the ether under like conditions. I discovered that I could utilize the steel rails of car-tracks as the wave-conducting medium and with comparatively indifferent instruments obtain better results for greater distances than that obtained with better instruments generating a larger spark and where the ether was used as the wave-conducting medium. The better the conductor the more excellent the results, and where I used wires along the tracks I found I could work with success to still greater distances than I really neededthat is, in connection with the means especially adapted for use on trains to prevent collisions. I further discovered that the present coherer and decoherer apparatus was unsuited and unsatisfactory for this particular kind of transmission and that the decoherer especially did not cause a uniform decohesion of the metal filings in the coherercylinder and which was partly the cause of its unreliability in operating a signaling device. Successful operation could be obtained for a short period only, and then the variation of the intensity of the Hertzian wave would cause a finer cohesion of the filings, which in turn resulted in slow decohesion. To overcome the above objections of every nature, I conceived and developed the following method and means fordespatching, conveying, and receiving the Hertzian wave to the best advantage and have further produced an apparatus whereby perfect signaling between two distant points can be automatically effected and which is of especial value in preventing collisions between trains on railroads, and the following description applies more particularly to this adaptation of my invention.

In the accompanying drawings, Figure 1 is a diagrammatic view of the combined apparatus comprising the transmitting and the receiving apparatus and conductor employed for the Hertzian wave with electrical circuits for all the parts in their connected relation.

Fig. 2 is an enlarged sectional elevation of the coherer and decoherer cylinder and its associated parts. Fig. 3 is a cross-sectioneof Fig. 2 on the line a: w.

Now presuming that the invention is used for railway signaling purposes, I place the sending or transmitting apparatus A upon one train and the receiving signal-alarm apparatus B upon another train upon the same track, the latter preferably in the cab of the engine in plain view and hearing of the engineer. The transmitting apparatus A comprises in this instance any well-known induc tion-coil device 2, having platinum breaks and oscillators 3 and 4, which are adjustably mounted and between which the spark is caused to jump togenerate the so-called Hertzian wave.

regular intervals by opening and closing an This spark is obtained at electrical circuit 5, having said oscillators electrically connected therein,and which opening and closing is effected by a timed or mechanically-operated switch comprising in this instance a clock mechanism 6, having a commutator disk or cylinder 7, mounted on the arbor or power-stem of the clock, and which stem is revolved at any desired speed, but preferably at about three revolutions per minute. A brush or strip of platinumor cop-- per 8 rides onsaid commutator, and the current through circuit 5 is automatically switched on and off as the commutator 7 revolves. The electric current can be furnished by a series of batteries 9 or by any other suit able source of electrical supply. This transmitter, as heretofore outlined, is placed upon a train. and preferably at the rear end thereof, and a wire connection 10 is made with either of the oscillators 3 or 4 and which connection leads to the axle-box of the car on which the transmitter is placed (or as shown) to a brush 11, mounted on the car or car-truck. By experiment I find that when the Hertzian wave is flashed from one oscillator to the other of the transmitter the Hertzian wave thus generated will follow the wire 10, and if the railroad-rails 12 are used as a medium of conveyance said wave will follow said rails in either direction, dependent upon the length and intensity of the spark generated. If a copper or other wire 13, as shown, is utilized in place of the rails as a conductor, said wave will travel a greater distance with less loss of energy, and in some instances I prefer to use a wire 13. In this case [employ a brush 11 to make contact with said wire. In practice I find that this wire may be connected direct to the ground, and yet there is no grounding of the wave or loss in intensity of its force, and I find further that said wave will follow said wire even though brush 11 is not in direct contact with it and, in fact, may be several inches or more from it at all times. For the purpose of blocking trains I use an induction-coil of sufficicnt capacity to throw out a wave that will travel one-half mile or up to five miles or farther, as may be needed.

To detect and utilize the Hertzian wave thrown from the train and transmitting apparatus heretofore mentioned, I place a receiving apparatus B, preferably, in the cab of an engine and connect the same by a wire 14:

with a brush 15 on the pilot of the engine, or if the rail is used as the conductor said wire is connected to the axle of the engine and the circuit is completed by the axle and the wheel to the rail. Among the other peculiar properties of this wave and in the method of utilizing the same it will be understood that no return or closed circuit, as in ordinary electrical operations, is required, but that the single metallic conductor answers every purpose. Therefore when the so-called Hertzian wave is generated and flashed over the conductor 13 from the transmitting appara tns A the receiving apparatus B is directly and immediately affected to operate an alarm or signal within the cab of the engine, and this latter apparatus in this instance is comprised as follows: A coherer and decoherer device or block 16, of gutta-percha or otherinsulating material and cylindrical in form, is mounted to revolve on an axis having bearings in post 17 and 18, respectively. The axis consists of two brass rods or trunnions 19 and 20, screwed into the ends of the cylindrical block 16, with their inner ends pointed and spaced apart about one-quarter to onesixteenth of an inch and with the points located about centrally from the ends of said block. A cone-shaped depression 21 is made at one side of the axial center ofblock 16, directly opposite the points of rods 19 and 20, and a covering of mica 22 or other material is fastened to said block to close depression or opening 21 from the outside and to confine a certain amount of metal filings within said depression. The normal position of depression or opening 21 is above the axial center of block 16, which causes the metal filings to rest within the apex of the inverted cone between the points of rods 19 and and in contact therewith. At the side of block 16 and upon rod or trunnion 20 I mount a cam 23 to hold and lock block 16 in its normal position, as heretofore described, and at the end of trunnion 20 is a pulley 24, to which power is transmitted from electric motor 25. The object of the motor 25 is to rotate block 16, and thereby cause the metal filings which surround and bridge the space between the points of rods 19 and 20 to fall away by gravity when depression 21 is brought below the axial center of rotation. Decohering of the metal filings is thereby accomplished, and upon further rotation of block 16 depression 21 again comes to the top and the filings again fall into contact with both points of rods 19 and 20 to reestablish a metallic circuit over the main line when a Hertzian wave is transmitted from the sending apparatus A over conductor 13 and wire 14:. Said wave passes from wire 1 1 to post 17, to which it is attached, and causes the cohesion of the filings, which action closes a local relay-circuit having a wire connection Z) with post 18, leading to battery 6 from said battery to the binding-post of relay and from binding-post Z) of said relay over wire 0" to post 17 to complete the circuit. Relay 6 when thus operated closes circuit 0, con-- nected with binding-post b" and b of the relay,

and an alarm or signal is in this instance accomplished by a bell O in said circuit 0 to notify the engineer of the dangerous proximity of another train on the same track. Relay 6 also closes a further circuit (Z, which starts certain mechanism to unlock cam 23 to permit block 16 to revolve. Thus circuit (Z .is connected with binding-post b and If of the relay 6 to operate a second relay or magnetoperated locking device d, which is provided with a spring-controlled armature 4Z having a pivoted locking-dog OZ mounted at or near the extreme end of the armature immediately below cam-disk 23 on rod 20 and normally in engagementwith theshoulderthereon. When the circuit d is closed, armature (Z is drawn down by the magnets of relay d, and dog 03 is lowered out of engagement with cam 23, thereby permitting it to be revolved; but in order that revolution of said cam can occur a further circuit must be established to operate motor 25, and this is eflfected by armature d striking a spring contact-strip a, mounted on post 6 and which contact closes the motor-circuit e and causes motor 25 to revolve at once. The moment it starts, dog d is prevented from rising by reason of its engagement with the concentric peripheral su rface of the now revolving cam 23, and therefore armature 0Z and strip 6 remain in contact and keep circuit a closed until a full revolution of block 16 is obtained and the notch and sh oulder of the cam 23 are reached. When armature (Z assumes its normal position under the action of its spring (2*, contact with spring a is again broken and the motor is stopped until the motor-circuit is again closed. This operation occurs at each transmission of the Hertzian wave after the filings in depression 21 have been brought to cohering condition and by the means of the several local circuits and connected apparatus, as heretofore outlined.

The filings within block 16 are of copper, coke, iron, and silver or their equivalent, the proportions of which may be varied, and the result sought for may be obtained by a combination of any of the filings above mentioned. Furthermore, the rods 19 and 20 are threaded and are adjustable in relation to each other at their pointed ends in order that the scnsitiveness for cohering purposes may be increased or lessened, as may be desired, so that a wave of a predetermined intensity may be controlled and utilized for diflerent distances from one-half mile upward.

I find upon experiment that when the Hert- Zian wave is flashed from one oscillator to the other of the transmitter on a caboose, train, or engine at the proper distance that a coherer of the kind described upon the approaching engine, either at the head or the rear, will cause the filings in said coherer to cohere together at the distance for which we prefer to use said instrument. These filings cohering together close the first local circuit to operate the relay, which in turn closes local circuit 0 to ring bell G. I also find that after the Hertzian wave has caused the filings to cohere they will not separate of their own accord after the spark has ceased to flow, and to cause suflicient separation or decohering of the filings I invented the rotary decohering apparatus, which has in no instance failed to work, as the separation of the filings are bound to occur through the positive action and mixing to which they are subjected.

It will also be understood that while I have entered more or less fully into the details of the instrument I have been using successfully for this purpose the invention is not necessarily limited thereby and that any sulficient instruments may be employed for receiving and sending which will work together and answer the same purpose of my invent-ion. With a metallic conductor to carry the wave the said wave will, however, not be limited to travel in only one direction on the rail, but, like other waves, will travel in opposite directions thereon, so that if there be approaching trains from opposite directions on the same track they will be signaled in like manner, assuming that both are equipped with corresponding instruments.

The time-controlled mechanism for control ling and regulating the number of flashes or transmissions of Hertzian waves at the transmit-ting apparatus is of great importance, because with this device each train may have its own peculiar and recognized call or alarmthat is, the commutators 7for each train may be varied in construction or the clock set at varying speeds to give a more or less number of flashes and transmissions of the wave per .minuteand whereby different trains on the same track can distinguish the signals received from the front or rear or both.

Receiving apparatus B may in some instances be located permanently at the side of the track or line, as at switches or dangerous crossings, to ring an alarm or give a signal in advance of an approaching train, and it is understood that my invention covers a Wide range of utility and is not limited to the mere adaptation of preventing collisions of trains,

as has been more fully described. Thus a fur- I ther use would consist in placing receiving instruments at intervals of a mile or two along the track and provide a block system for the safety of the trains and somewhat similar to the block system now in use.

I have preferably shown and described the invention in connection with railway service and use; but it is not necessarily limited to such service and may be employed in other places and for other uses as it may be found available.

What I claim is 1. In a signaling apparatus, the combination of an electrical wave-generating apparatus, a receiving apparatus for said waves comprising a coherer and decoherer device, a motor to actuate said device, controlling mechanism for timing the movement of said motor, a relay electrically connected with said controlling mechanism and with said coherer device, a signal device controlled by said relay, and a main-line metallic conductor having terminal wire connections between said generating and receiving apparatus and said main conductor, substantially as described.

2. In means for signaling between railwaytrains, the combination of a sending apparatus comprising a Hertzian-wave generator and a timed controller therefor,a Hertzian-wavereceiving apparatus comprising a coherer and decoherer device and actuating mechanism therefor, a timed controller for said device and said mechanism, a relay electrically connected with said coherer device and with its timed controller, a signaling device operated by said relay, a main metallic conductor stretched parallel with the railway-track, a wave-transmitting member carried upon one train in close relation with said conductor but out of contact therewith, and wire connections leading from each apparatus to said member and main conductor, substantially as described.

3. In signaling apparatus for trains, the combination of an electrical wave-sending apparatus with a receiving apparatus for the wave comprising a coherer device and actuating mechanism for said device, a relay electrically connected with said coherer device and with said actuating mechanism to time the movement thereof, a signaling device operated by said relay, a main metallic conductor R. B. Mosnn, H. G. REHN. 

